JPS6435616A - Constant-current circuit - Google Patents
Constant-current circuitInfo
- Publication number
- JPS6435616A JPS6435616A JP19008987A JP19008987A JPS6435616A JP S6435616 A JPS6435616 A JP S6435616A JP 19008987 A JP19008987 A JP 19008987A JP 19008987 A JP19008987 A JP 19008987A JP S6435616 A JPS6435616 A JP S6435616A
- Authority
- JP
- Japan
- Prior art keywords
- current
- constant
- error
- widler
- variation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Abstract
PURPOSE:To decrease a variation of an output current at the time of variation of a current amplification factor, by converting an error current generated in a Widler constant-current circuit, to an error voltage, and applying a negative feedback to the Widler constant-current circuit through a transconductance amplifier. CONSTITUTION:By a drop of a current amplification factor of PNP transistors Tr Q11, Q12 for constituting a Widler constant-current circuit, a current error of each collector current I1, I2 generates the same currents I1', I2' as the currents I1, I2 by Trs Q15, Q16 and a resistance R12. Subsequently, it is converted to a voltage error DELTAVd by resistances R13, R14. Next, this error DELTAVd is converted to a current IF by a transconductance amplifier TCA and applied to a collector connecting point of the Trs Q11, Q13 of the Widler constant-current circuit, by which a negative feedback loop is constituted. That is, a loop of (current IB large) current difference I-I2 large) (current difference I1'-I2' large) (IF large) (current difference I1-I2 small) is constituted. In such a way, a variation of an output current at the time of a variation of a current amplification factor can be suppressed small.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP19008987A JP2663449B2 (en) | 1987-07-31 | 1987-07-31 | Constant current circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP19008987A JP2663449B2 (en) | 1987-07-31 | 1987-07-31 | Constant current circuit |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6435616A true JPS6435616A (en) | 1989-02-06 |
JP2663449B2 JP2663449B2 (en) | 1997-10-15 |
Family
ID=16252181
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP19008987A Expired - Lifetime JP2663449B2 (en) | 1987-07-31 | 1987-07-31 | Constant current circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2663449B2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08314561A (en) * | 1995-05-19 | 1996-11-29 | Nec Corp | Starting circuit |
US6031414A (en) * | 1997-06-30 | 2000-02-29 | Nec Corporation | Constant current circuit with small output current fluctuation |
-
1987
- 1987-07-31 JP JP19008987A patent/JP2663449B2/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08314561A (en) * | 1995-05-19 | 1996-11-29 | Nec Corp | Starting circuit |
US6031414A (en) * | 1997-06-30 | 2000-02-29 | Nec Corporation | Constant current circuit with small output current fluctuation |
Also Published As
Publication number | Publication date |
---|---|
JP2663449B2 (en) | 1997-10-15 |
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